This invention relates to apparatus for packaging and for using self-developing photographic film and, in particular cassettes of self-contained self-developing film units.
Self-developing cameras, which position, expose and effect development of photographic film, have been used by industry and the consuming public for many years. The earliest cameras use roll film in which a photosensitive sheet is exposed and brought together with a contact sheet carrying a rupturable container of a fluid photoprocessing composition. The sheets pass through aligned rollers to rupture the container and spread the photoprocessing composition between the sheets. After development with the photoprocessing composition, the user peels the two sheets apart.
Later self-developing cameras use cassettes having a set of photosensitive sheets and an equal number of insensitive sheets. Two sheets, one from each set, again are brought into contact after exposure. After passing through spread rolls and development, the sheets are peeled apart.
Recently, cassettes of self-developing units of film have been introduced in which each film unit is totally self contained. The film unit is denoted as being "self contained" because, in contrast to the prior "put together" and "peel apart" film noted above, the initial laminar configuration of each film unit remains intact throughout exposure, processing and ultimate use of the photographic product. The laminar film unit structure thus is not changed, either by bringing sheets together or by peeling sheets apart. U.S. Pat. Nos. 3,415,644; 3,651,746; and 3,779,770 disclose a form of self-contained film unit which is exposed from the same side on which the photographic product is viewed, and disclose containers for packaging them. U.S. Pat. Nos. 3,761,271 and 3,765,887 describe self-contained film units which are exposed and viewed from opposite sides, and describe containers for holding them.
The self-contained film units provide multiple user advantages, including freedom from having to bring two sheets together, from having to time the development interval, and from having to peel film sheets apart. However, the new film units have been capable of use only in correspondingly designed cameras, and not in prior cameras designed for use with the cassette-packaged "peel-apart" types of self-developing film.
Others have suggested ways of using self-contained self-developing film units in the older cameras, but their constructions have not been adapted commercially. See, for example, the above-noted U.S. Pat. Nos. 3,765,887 and 3,761,271.
It is, therefore, an object of this invention to provide a photographic film cassette of self-contained self-developing film units for use in older cassette-loading cameras which have hitherto been unable to employ the new self-contained type of film. Other objects of the invention include providing such a cassette of self-contained film units which can be used in an older, cassette-loading camera without modification to the film-handling portion of the camera, which provides generally the same number of exposures as the multiple sheet cassette for which the camera was designed, and which is simple to load and use. It is also an object of the invention that the cassette of self-contained film units operate with high reliability, particularly in a camera which relies entirely on manual transport for the film advancing and processing operations.
Another object of the invention is to provide a means for transporting self-contained units of self-developing film in a camera designed for cassette-loaded peel-apart film.
Other objects of the invention will in part be obvious and will in part appear hereinafter.